Abstract:At present, there are still many key problems to be solved in the monitoring and warning system of overhead lines icing in the South China Power Grid, such as the selection of parameters in the core calculation of the system is relatively simple, and there is no actual line design conditions. Therefore, the model of icing early warning system is inaccurate and can not provide effective decision-making basis for the anti-icing management and control work. Therefore, this paper firstly analyzes the calculation error of the existing ice thickness model of tension tower line in the system, and then improves the model from the point of view of line design. The results show that: (1) the existing calculation models neglect the influence of the initial design ice thickness and the variation characteristics of the vertical gear spacing; (2) the initial tensile force is corrected by the improved calculation model, and the design ice thickness, the vertical gear spacing, the horizontal stress, the traverse equation of state and other characteristics are taken into account. The improved model can improve the accuracy of the existing calculation model from 59.8% to 95.1%, and the calculation results are closer to the real value. The conclusions of this paper can provide effective decision-making basis for the transmission department to provide anti-icing management and control work, and reduce the cost of artificial ice observation resources and time.